Lads....

While sitting, idling at a traffic light or in my driveway while warming up, with lights on, there seems to be a brief drop in voltage, slightly dimming my lights. The drop is very brief, and it cycles pretty regularly.

Is this indicative of a potential problem or with the weather turning colder here in the NE, is this normal? I seem to remember some discussion about a "grid heater". Can someone explain this to me and do you think this could be my situation?

Thank you in advance for your insight.



***EDIT***
The search feature is your friend. I just found a thread started in 2004 that addresses this very situation.
I am now a frim believer of the search function. Thanks for your time. Mods, pls delete post if necessary.

 

Welcome abaord anyways!

 

It should go away once you’re warmed up. I use the search button every day only to get 1500 posts of things completely irrelevant. I am definitely not the Goggle master!

 

Just a quick response in case someone stumbles on this thread - if cold, the grid heater pre-heats before you start the truck. Once it's running, the grid heater will cycle on and off depending on intake temperature etc. You'll see the voltage drop(lights dim etc) for a few seconds, then back up to ~14 volts, then back down, repeats until the ECM is satisfied.